The 38-year-old German man stole an excavator from a construction company in the town of Grünsfeld, south of Frankfurt, where he reportedly destroyed the entire inventory during the rampage on Tuesday.
Investigators on Thursday said he was previously employed by the construction company.
Details about what he did with the company and whether he was fired or resigned remained unclear, according to a spokesman for the public prosecutor's office.
The man also drove the excavator to a nearby car dealership, where he also caused destruction.
According to prosecutors, the owner of the construction company also owns the car dealership.
The man injured several police officers and damaged four police vehicles during a roughly hour-long chase that stretched across several kilometres.
There is no indication that the man was suffering from mental illness, the spokesman said.
He added that the total cost of damage has not yet been calculated.
The public prosecutor's office is also investigating the police decision to fatally shoot the man.
It is still unclear exactly how many shots were fired at the excavator driver but several officers fired their weapons during the incident, the spokesman said.
At the moment, however, he said that there is no evidence of any misconduct on the part of the police.
